//
//  YanOAuthViewController.swift
//  SinaWeibo
//
//  Created by mac on 2017/5/9.
//  Copyright © 2017年 mac. All rights reserved.
//

import UIKit
import SVProgressHUD

/// 通过webView加载新浪微博授权页面控制器
class YanOAuthViewController: UIViewController {
    fileprivate lazy var webView = UIWebView()
    
    override func loadView() {
        view = webView
        webView.delegate = self
        view.backgroundColor = UIColor.white
        webView.scrollView.isScrollEnabled = false
        // 设置导航栏
        title = "登录新浪微博"
        // 导航栏按钮
        navigationItem.leftBarButtonItem = UIBarButtonItem(title: "返回", target: self, action: #selector(close), isBack: true)
        navigationItem.rightBarButtonItem = UIBarButtonItem(title: "自动填充", target: self, action: #selector(autoFill))
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()

        // 加载授权页面
        let urlString = "https://api.weibo.com/oauth2/authorize?client_id=\(WBAppKey)&redirect_uri=\(WBRedirectURI)"

        // 1.URL 确定要访问的资源
        guard let url = URL(string: urlString) else {
            return
        }
        // 2.建立请求
        let request = URLRequest(url: url)
        // 3.加载请求
        webView.loadRequest(request)
    }
    
    @objc fileprivate func close() {
        SVProgressHUD.dismiss()
        
        dismiss(animated: true, completion: nil)
    }
    
    /// 自动填充 - WebView的注入，直接通过 js 修改 ‘本地浏览器中’ 缓存的页面内容
    /// 点击登录按钮，执行 submit() 将本地数据提交给服务器
    @objc fileprivate func autoFill() {
        // 准备js
        let js = "document.getElementById('userId').value = '';" + "document.getElementById('passwd').value = '';"
        webView.stringByEvaluatingJavaScript(from: js)
    }

}

extension YanOAuthViewController: UIWebViewDelegate {
    
    /// 将要加载请求
    ///
    /// - Parameters:
    ///   - webView: webview
    ///   - request: 要加载的请求
    ///   - navigationType: 导航类型
    /// - Returns: 是否加载 request
    func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebViewNavigationType) -> Bool {
        // 思路：
        // 1.如果请求地址包含http://baidu.com 不加载页面，否则加载页面
        // 2.如果从http://baidu.com 回调地址的 ‘查找字符串’ 中查找 ‘code’.有，授权成功，否则授权失败
        if request.url?.absoluteString.hasPrefix(WBRedirectURI) == false {
            return true
        }
//        print("加载请求 --- \(request.url?.absoluteString)")
        // query 就是URL中 ‘?’ 后面的所有部分
//        print("加载请求 --- \(request.url?.query)")
        if request.url?.query?.hasPrefix("code=") == false {
//            print("取消授权")
            close()
            return false
        }

        // 3.从query字符串中取出授权码
        let code = request.url?.query?.substring(from: "code=".endIndex) ?? ""
        print("授权码 --- \(code)")
        // 4.使用授权码获取AccessToken
        YanNetworkManager.shared.loadAccessToken(code: code) { (isSuccess) in
            
            if !isSuccess {
                SVProgressHUD.showInfo(withStatus: "网络请求失败")
            } else {
                SVProgressHUD.showInfo(withStatus: "登录成功")
                // 通过通知发送登录成功消息
                // 1.发送通知
                NotificationCenter.default.post(name: NSNotification.Name(rawValue: WBUserLoginSuccessedNotification), object: nil)
                // 2.关闭窗口
                self.close()
            }
        }
        
        return false
    }
    
    func webViewDidStartLoad(_ webView: UIWebView) {
        SVProgressHUD.show()
    }
    
    func webViewDidFinishLoad(_ webView: UIWebView) {
        SVProgressHUD.dismiss()
    }
}
